A Secure Voice Channel using Chaotic Cryptography Algorithm

A secure voice communications channel is on demand to avoid unwanted eavesdropping of voice messages. This paper reports the development of communicaiton channel prototype equipped with Chaotic cryptographic algorithm with Cipher Feedback mode, implemented on FPGA due to its high processing speed and low delay required for voice channel. Two Spartan-3 FPGA board was used for the purpose, one as transmitter in encryption process and the other as receiver of decryption process. The experimental tests reveal that the voice channel is successfully secured using the encryption-decription cycle for asynchronous communication. In the non-ecrypted channel, the average values of MSE, delay, and THD-N parameters are 0.3513 $\textbf{V}^{\textbf{2}}$, 202 μs, and 17.52%, respectively, whilethe secured channel produce MSE of 0.3794 $\mathbf{V}^{\mathbf {2}}$, delay 202 μs, and THD-N 20.45%. Therefore, the original information sent in the encrypted channel can be restored with similar quality compared to the non-encrypted channel.